Indian River Inlet Bridge, Delaware

Project Summary

Demolition of Haunched Steel Girder Bridge

Indian River Bridge is a steel plate girder bridge, originally built in the 1979's, that varies in depth from 7'-0" at mid span to 14'-0" at the Piers. The total length of the bridge is 874 ft with a 250 ft spans over the tidal inlet. Seawater rushes in and out of the inlet at speeds up to 15 knots at high and low tides twice a day. The constant scour of the seawater on foundations of the piers undermined the foundations which led to the State of Delaware's decision to replace the bridge with the new cable stayed structure.

Summit Engineering developed the removal plan for the existing bridge. Due to the swift, alternating current in the channel and poor soil conditions along the banks, conventional methods of removal using barges and cranes were not allowed. A unique reverse a launching system was designed to remove each half of the northbound and south bound bridges. Each bridge was strengthened with a unique "Queen Post" system, cut in half over the inlet channel, raised with hydraulic jacks and placed on rollers. The half section of bridge was then pulled from the channel by rolling the spans on to the embankements at each end of the bridge where they were cut up for scrap.